enough yapping---grizz x3 //ordered// RECEIVED

[project5k]

Well i finally had enough talking, it was time for action, so this morning i ordered my x3 from grizzly.. also got some center cutting end mills, a hold down kit and some collets.. I'll add pictures and information as the parts start showing up... now its time to order mach 3.. but i had a problem, on thier website where it said to click the credit card logo to order, clicking it didnt get me anywhere.. anyone else experienced this? whats the easiest way to get my mach here?

i'm also going to order the cnc fusion kit.. just the little 3 axis kit for now as i'm running outta money and they dont have any ball screws right now anyway... I contacted them and asked if they could supply the z axis as a nema 23 rather than the standard nema 34 as i already have 3 500oz 23's that i'm going to use till i can get my ball screws...

a question on coolant, i'm thinking that i should run a flood coolant type system.. i have several little pumps, 2 167 gall/hr and 3 68 gall/hr pumps.. these are "clear water" pumps, but all they really are is little centrifigul pumps, so as long as i keep any chips outta them they should work, i think... i'm currious as to what the viscosity of the coolant is, is it about as thin as water, of considerably thicker? what kind of coolant should i use as i will be cutting mostly copper and alum... grizzly sells a gallon of stuff you mix 50/50 with water to make 2 gals of coolant, cant use this with titanium, but thats not a concern for me... can i use this? is there something better for less than like $50?

what about all the stuff i have read about it going rancid? stinking and stuff.. does this make the coolant really go bad, or just make it stinky? is there something that i can do to help prevent this? i was wondering if i could use an aquarium air pump and a couple areators to keep it moving in the pump tank while not in use...

ideas? suggestions??

Joe
Seguin, TX

[digits]

Congratulations on your new machine - I hope you enjoy it!

As for coolant, I use a water-soluble oil that mixes 1:25 with water to produce a thin, milky fluid. So far I haven't had much of a problem with bacterial contamination of my coolant bucket, but stagnant little pools left in my enclosure do smell nasty after a couple of days - I gess it'll be more of a problem in the summer though...

[Ron111]

Joe,

Glad to see another X3 underway. I use Rustlic and I forget the number and I mix it like 10 oz / gal, so it lasts a good while. I ordered it from MSC and with shipping it is around $45 or $50.

The 500 in/oz for the X will do fine especially if you use a gas spring.

As fat as Mach 3, I would just email Art @ artofcnc.com and let him know your having problems. You can go ahead and down load the software and the user's manuel where you can get it figured out. The software will be in the "Demo" mode and will limit the program to 1000 lines and when Art sends you your licience# and you install it then you will be set.

Congrads,

Ron

[project5k]

i have the demo of mach 3, i've been using it to test out driver boards that i made.. 4A/phase bipolar. seems to work splendiferously! hehehe anyway, i need to finish making my powersupply.. converting 9 computer powersupplies and then linking the 5v lines in series to give me 45v and 25A... that should be enough power in reserve for when i add a 4th axis, and to run a few little extras...

thanks for the info on the coolant.. as this is my first mill, i still have lots to learn,

one other question i had, i have the demo of mach on my office machine for now... once i have the liscense, can i then move or copy that over to the machine computer out in the shop?

and for as long as i've been on cnczone, i've found nothing but people willing to help... Thanks again!

[BZER1]

And yet another...I went out to Grizzly last weekend and picked up my X3. I unfortunately have not had time to touch it since then but I'm thinking this weekend will be the perfect time to do a good cleaning and spindle break in. I'm waiting for a while to do the conversion so I'll start making some chips manually until I can afford the cncfusion and Xylotex kits. Besides I'd really like to spend some time getting to know my new addition before I upgrade it. I have a few projects going on right now that don't require a CNC machine so I can actually make very good use of the machine right away.

[NC_jimbo]

Project5K said........."converting 9 computer powersupplies and then linking the 5v lines in series to give me 45v and 25A"

Careful. Do you know this works? Standard PC power supply has its output grounds electrically tied to the AC input ground. Do you somehow have supplies with isolated output grounds?

[digits]

I'd agree, linking switchmode PSU's in series sounds like a really bad idea - you can build a linear PSU in just 4 components : transformer, bridge-rectifier, capacitor and a fuse - but if you don't know your amps from your volts, you'd be better off just buying a beefy PSU - 45v * 25A = one large bang if things go wrong...

[sbalder]

Congrats on the X3! I had one as my second CNC conversion, with linear slides driving the carriages. That machine is a great value.

A few thoughts-

1)If money is an issue I would give serious consideration to selling the 9 power supplies as a lot on Ebay and using the money to buy a good 5 amp switching supply. I bought a few new on Ebay for $30 a piece. Remember, your PS current will be less than the rated current of your steppers.

2)In my opinion a flood coolant system is not practical for this size machine. For $60 you can get a Trico mist coolant unit (Enco # 296-2340). I had on on my X3 where I had added a needle valve off of a model airplane engine to the coolant line. This gives a precise control of both air and coolant. On my X3 I added an adapter for a router spindle. For wood and carbon routing I only needed compressed air. For machining I would use air and mist.

Good luck!

[tai42]

NC_Jimbo is correct. In order to hook up the output of two power supplies in series, the outputs must be "floating" and not tied to any common ground. You can check this by turning a couple of the power supplies on and hooking a volt meter to the positive of one supply and the negative of the other. If you get a reading, then the output is not floating. If you hook the two together you will create a short and let the smoke out of the electronics.

[NC_jimbo]

Tai42, yep, or simply doing a ohmage between output ground(black wires) and the third round prong ground contact of input 120VAC you will find that it is probably 0 ohms. Thus when you connect the 5V (red wire) of the 1st supply to the black wire of the 2nd supply you are effectively shorting the 5V to ground.

On a cheap power supply, you may kill it, on the better power supplies an overcurrent protection circuit will prevent supply from coming fully on. You'll see the fan spin for a second and then stop.

There's a really cheap BUy It Now Ebay store (mentioned numerous time here) that has a lot of advocates here.

[tai42]

Tai42, yep, or simply doing a ohmage between output ground(black wires) and the third round prong ground contact of input 120VAC you will find that it is probably 0 ohms. Thus when you connect the 5V (red wire) of the 1st supply to the black wire of the 2nd supply you are effectively shorting the 5V to ground.

I've actually run across at least one power supply where the output was floating until it was switched on. (You can guess how I found out! ) This wasn't a PC supply, but since then I always do the "hot" test as well as checking the resistance if I'm going to be hooking something up in series. (Pretty rare - usually only if I need bi-polar and can't find a real bi-polar supply sitting around.)

I'm also a big fan of the idea: One ground to sink them all. One ground to tie them. One ground to bring the wires, and in the chasis bind them. (Ok, I'm probably not the first to think of that.) But with a CNC system, noise is the enemy, and he lives in ground loops. (Which makes floating power supplies all the more important since you actually have a chance of ground path management.)

Forgot to add, I also won't use switching supplies in a CNC setup. I've gotten burned before on other projects with noisy switchers, so everything outside the computer is big and linear.

[project5k]

ok, ok, yes, i do know about the grounds, and if you do the research there are several sites on the web that will explain how to do the conversion from tied to floating.. actually one thing that the sites don't cover is the jumper that you have to add to re-connect the 2 ground planes inside the unit.. the case is used to connect them when the unit is in stock configuration, so by removing the case from the equasion u cause an open between them... i have done this several times with great success.. considering that i'm a EE, and a TE, i think i can handle a little SMPS.
sorry that the attached pictures are blurry, i just reached over on the desk here and shot them with the webcam....

this was one of the first ones that i converted and put back into the case.. i used a neoprene spacer to make sure that the grounded lugs, which are through hole plated, didnt accidentilly touch the case.. and then i just didnt put the screws back into that mounting hole... i have been using 2 set up this way as a bench supply, for years

the actual conversion dosent take long at all.. you just have to make sure that they are AT powersupplies and not ATX....

the other thing that you have to do is to load either the +5 line or the +12 line or both depending on the particular model of PSU that you are using as it uses this to determine regulation voltage and load... i just used a couple small resistors that i soldered across the key points on the board...
if these lines are left unloaded then the powersupply will go into a shutdown mode... too much load and it will shutdown due to "short sense"

you have to be carefull about your loadings of the different lines, some like the +5 line on the ones that i have are good for 25A.. but the -5 line will only do .5A...

I'm using the +5 lines because they have the highest current output... i could just as easily series the +12 lines to make 24, or 36, or 48v but it wont do the current....

as for the noise issue, a real nice slick way to fix that is to just run a nice fat cap across the output through a resistor.. remember that "short sence" i was talking about.. when you first fire up the PSU set, it will see that cap as a short... by having the resistor in there, it will charge the cap, clean up any switcher noise, soften the pulse draw load of motors starting and stopping, and generally make for a better supply...

I've done this on several ham amps that were set up for 48v, i just used 10 PSU's..

it works, i promice, and you can really get around 20-25A at 45V... if you know what your doing, and are safe around open line voltages that is... cause the reality is that if you dont know what your doing, and you grab hold of one of these things, even after its been unplugged for a couple weeks, it can still drop you to your knees.. thoes caps can pack a punch...

sorry for jumping up on my soap box, but it cought me off gaurd when something that i've been doing for years was bashed.....

bottom line, AT PSU's are out there for the taking, thus free... and thats just the right price for me.. besides, it was a fun project....

once i get all the ones that i'm going to use for the cnc machine done and mounted, i'll take pictures...